PROCESS FOR LARGE AMOUNTS OF WASTEWATER DESINFECTION AND TREATMENT, WATER RECYCLING AND

UTILIZATION OF ORGANIC AND INORGANIC CHARGES Invention Field The present invention right patent, PROCESS FOR LARGE

AMOUNTS OF WASTEWATER DESINFECTION AND TREATMENT, WATER RECYCLING AND UTILIZATION OF ORGANIC AND INORGANIC CHARGES has as its object a practical and innovative process of organic wastewater treatment, pertaining to the recycling techniques field, most precisely utilized on fermented most distillation by the time of the manufacturing of alcohol or alcoholic beverages, aiming to improve its utilization and development in connection with other processes generally found at the market. It concerns therefore with a process which was perfectly and efficiently developed, for the purpose of offering a process for the wastewaters treatment with the object of degrading pollutants substances and recycling wastes and effluents produced in it, proportioning a great reliability to which it is of service, either by its functional characteristics or by the practicability of the process.

It is also, object of this invention right request, to present a process that promotes pollutants degradation and that treat large amounts of wastewaters at low costs for its industrial feasibility, allied, nevertheless, to the sanitary safety and utilitarian practicability requisites, thus offering to the consumers an additional option on the congeners market, that unlike the usual processes, offers a number of possibilities and benefits to its users, turning into a model of great acceptance on the consumer market.

Invention Background

As it is commonly known, vinasse is the name given to the effluent generated on fermented must distillation by the time of the alcohol or alcoholic beverages production from the fermentation of vegetal inputs like sugar cane, beet root and other tubercles and roots, maize and other cereals, cellulose, and other materials containing carbohydrates. On the case of sugar cane it is generated on large amounts, from 10 to 18 liters by produced alcohol liter, and leaves the distillation apparatus at temperatures of the order of 85 ⁰ C to 90 ⁰ C, consisting of a toxic effluent with an elevated pollutant power, mainly resulting from its considerable organic charge, intense coloring and low pH, being characterized by elevated Oxygen Chemical Demand - COD , e de Oxygen Biochemical Demand - BOD indexes, being for this reason highly prejudicial to the flora and fauna and specially to the water ways, besides its infiltration in the soil which also contaminates subterranean waters by reaching the water-bearing strata.

The considerable presence of recalcitrant phenolic compounds on the vinasse organic charge is the main reason by which such effluent is so prejudicial to the environment.

Besides environmental damages, the vinasse's slow natural degradation exhales both strong and unpleasant toxic odors exposing the workers and the entire population to health problems. The consideration granted to the vinasse's treatment methods development has increased a lot on the last years, mainly regarding the great demand for the use of ethanol as a fuel; such fact has multiplied the number of producing plants and consequently environmental problem arising from the huge quantity of vinasse

generated.

As it is well-known by technicians from this field, several methods have been developed and suggested for the vinasse treatment, however in its great majority such methods collide with difficulties as high operational cost and technical impracticability due to the huge quantity of effluent produced uninterruptedly.

Methods that include organic charge direct biodegradation (see patents BRPI830502; BRP18701488 A; UM 8502073-7U) do not seem to be completely efficient, for the considerable presence of recalcitrant phenolic compounds delays the biodegradation kinetics due to their germicide properties.

Methods that include effluents' pre-oxidation with the purpose of eliminating the resistance of phenolic compounds to biodegradation, they accelerate the biological process (see patent USPN 5.851399), although, in case of vinasse again the huge amount produced demands technological solutions enabling its treatment into larger amounts and bigger rapidity. Another possibility that has also been explored is the vinasse's physical-chemical treatment, which basically comprise of its neutralization, coagulation and flocculation. (see patents FR 2529568 A1 ; BRPI 8705131). This type of treatment has as its culminating point the possibility of decreasing the OCD, however in larger amounts its results are partials, still due to the permanence of recalcitrant phenolic compounds on the organic charge. The photocatalyzed AOP (Advanced Oxidation Process) methods utilization has also been experimented, mainly through processes that use Fenton reagent (see J. Beltran de Heredia et. Al., Water Science and Technology, VoI 51, No. 1 , pp 159 -168

(2005)). Methods that include electrodialysis (see patent BRPI 0505211 - 4A), electrolytic degradation (see patent BRPI 8206309 A), and even incineration and water evaporation have been proposed (see patents BRPI 8220577; EP 0048061 A3; EP 0794246 A1), however while considering the vinasse's huge amounts produced, major problems connected to the "scale up" appear, besides prohibitive operational costs. All of that succeeded in the vinasse's direct sprinkling at the sugarcane plantation has been pondered as a practical solution for such problematic; however due to the material's toxicity and to potassium's high concentration that unbalance the soil's ionic change characteristics, this simple and pure practice is been widely contested in regard with the environmental issue. Defective issues of the state-of-the-art The great inconvenience of these models consists on the vinasse's slow natural degradation that exhales both strong and unpleasant toxic odors exposing the workers and the entire population to health problems.

Methods employed, which may include organic charge direct biodegradation, are not efficient, for the presence of recalcitrant phenolic compounds delays the biodegradation's kinetics. While those which include pre-oxrdation of effluents accelerate the biological process, however the huge amount produced demands technological solutions that enable its treatment in larger amounts and bigger rapidity.

Methods that execute the vinasse's physical-chemical treatment enable the COD decrease, although in larger volumes its results are partials, due to permanence of recalcitrant phenolic

compounds in the organic charge. Those metres'' wftierr tficSlϋtie electrodialysis and incineration and water evaporation are also utilized, however the vinasse' huge amounts produced generate problems connected to the "scale up", besides prohibitive operational costs. And vinasse's direct sprinkling at the sugar cane plantation is a solution, although such pure and simple practice is contested in regard with the environmental issue. Summary of the invention

Thinking about such inconveniences, after a number of researches and studies, the inventor, a person who join the branch, created and developed the object of this patent, idealizing a process of organic effluents treatment seeking to obtain a process of disinfection and treatment of effluents on great volumes with water recycling, com the smallest number of stages as possible, conveniently set and arranged to allow that the process performs its functions with unique efficiency and versatility, without the inconveniences already mentioned.

A practical and innovative treatment process is presented in this patent request containing all the technical and functional qualities, elaborated and developed following the latest technicalities, enabling thus its most varied utilization, from the use on vinasse treatment in great amounts to its use for the treatment of other types of organic effluents produced on large scale, especially those containing substances recalcitrant to biodegradation. Its innovative technique allows the obtainment of an excellent effectiveness level, offering a process of degradation, which has a great efficiency, being created, mainly, for the application on great volumes with water recycling and organic and inorganic charges

utilization.

The process configuration, object of this patent, into its new constitutive form, comprises a method that renders possible the vinasse's treatment into great amounts, rendering it acceptable in regard with the environmental issue. The invention may be applied also to treat other types of organic wastewaters produced in large scale, especially those containing substances recalcitrant to biodegradation.

The wastewater is submitted to a disinfection and degradation process which consists into stages of oxidation, biodigestion, coagulation, flocculation, photo-oxidation and deminerafization, in a way that the solid waste resulting from the treatment might be utilized as fertilizer or nutrient; the biogas used as energy source, and recycled water at the process utilized for irrigation and other purposes.

One might comprehend thus that the process at issue is extremely simple in its constructtvity, being, therefore, of easy feasibility; however, there are obtained excellent practical and functional results, offering an innovative result in connection with the known processes.

Brief description of the process drawing

Below, for a better understanding and comprehension on how the PROCESS FOR LARGE AMOUNTS OF WASTEWATER

DESINFECTiON AND TREATMENT, WATER RECYCLING AND UTILIZATION OF ORGANIC AND INORGANIC CHARGES is constituted, herein pleaded, the block diagram is presented herein.

FIG.1 - Shows a block diagram containing the process stages, herein at issue.

Detailed description of the invention

As provided for the block diagram, the PROCESS FOR LARGE AMOUNTS OF WASTEWATER DESiNFECTION AND TREATMENT, WATER RECYCLING AND UTILIZATION OF ORGANIC AND INORGANIC CHARGES, object of this patent, is essentially characterized by a novel um process for the vinasse's treatment which might be extensible to other organic effluents produced in large amounts, it consists on the improvement and on the utilization of several techniques jointly with the purpose of degrading pollutant substances and recycling waste effluents produced on treatment, in a way that environmental and economical benefits may be reached; here disposed in stages to a better technical explanation, identifying the sequence of necessary operations. On the first stage the wastewater is submitted to an ozonization process (1).

On the second stage of the process the effluent is submitted to a biodigestion process (2).

On the succession, after the pH adjust, vinasse is submitted to a process of coagulation and flocculation where a substantial part of the organic charge is separated from the fluid phase (3).

The supernatant fluid is then, submitted to a process of advanced photo-oxidation (4).

Then it is accomplished the demineralization of the remaining fluid, after that the fluid already containing low levels of OBD is recycled (5).

1 - The stage of ozonization aims at the oxidation of organic- origin recalcitrant pollutants, as for example, phenolic substances

found in vinasse (see review Yung-Chien Hsu et al. Chemosphere, 56, pp 149-158 (2004)). In this stage the effluent's pH must be adjusted between 1.5 e 8.5; more rather between 2.5 and 5.5; rather between 3.5 and 4.5. Considering great wastewater flow, as it is the case of the vinasse, it is necessary an ozonization that may be fast and efficient enough. The amount of ozone to be sparkled in 1 dm ³ of vinasse is adjusted between 1.0 and 1000 g/h, more rather between 100 and 800 g/h, rather between 10 and 100 g/h, and the sparkling time must be between 10 seconds and 120 minutes, more rather between 10 seconds and 60 minutes, rather between 30 seconds and 30 minutes. These conditions are enough for the oxidation of levels between 50% and 80% of the phenolic substances found in the vinasse; such percentage must be rather between 70% and 80%. With these conditions there is verified the selectivity of the ozonization of bioresistant substances found in the neighborhood as polyphenols and unsaturated acids, raising biodegradability, enabling that on the following stage there may be biologically degraded a higher amount of wastewater on less time. On a typical situation, using ozone flow of 0.01 g/Liter/Hour, sparkled on 600 ml of vinasse for 30 minutes phenols sample concentration initially at 1.28 mg/Liter goes to 0.59 mg/Liter, suffering a drop of 54% on its original level. The exposure of the sample to more than 30 minutes, or the raise of the ozone flow to 0.015 g/Liter/Hour for 30 minutes lead to a drop of 56% on the percentage of phenols comparing to the original levels. (Analytical Method used: Standard Methods for the Examination of Water and Wastewater- 21 edition. Colorimetric Method No. 5530C).

Due to the occurrence of such phenols oxidation, reaction efficiency dependence to the exposure of these molecules to ozone, both by the raise of sparkling time and by the raise of ozone flow it is possible to raise the percentage of degradation of these compounds by raising its exposure to ozone, enabling thus the treatment of great amount of wastewaters on less time.

In order the ozone may be introduced efficiently to high flow of vinasse it is necessary to use suitable reactors that are characterized by elevated capacity of ozone generation and to promote an efficient mix of gases with fluids be it by means of agitation or spinning.

2 - After the ozonization the effluent passes by urn process of anaerobic biodigestion (see M. H. Gerardi, "The Microbiology of Anaerobic Digesters", Wiley Interscience, New Jersey (2003)). For such its pH must be pre-adjusted between 6.5 and 7.5, rather between 6.8 and 7.2, and more rather between 7.0 and 7.2, having the temperature adjusted between 10 ⁰ C and 40 C, rather from 25 ⁰ C to 35°C, more rather from 30 ⁰ C to 35°C. In these conditions it is observed a great performance of the mesophyll anaerobic microorganisms, responsible for biodegradation. For the case thermophyll anaerobic microorganisms are utilized, temperature shall be adjusted between 40 ⁰ C and 70 ⁰ C, rather between 50 ⁰ C and 65°C, more rather between 5O ⁰ C and 55 ⁰ C.

Bioreactors may be utilized, like those UASB (Upflow Anaerobic Sludge Blanket)-type, mixed bed anaerobic filters, fixed bed anaerobic filters, ascending or descending, the last ones with several types of polymeric, clayish, zeolitic beds, and even those of vegetal origin like vegetal fibers or sponges like those of Luffa

cilindrica sponge. What is requested is that the bioreactor may be utilized continuously, supporting great effluent flows with the least of entrainment of its microorganisms that must be fixed on its beds. The flow must run as slower as possible. Biogas formed on the process is recycled and it might be utilized on heating parts of the system itself, or as a fuel.

3 - On the next stage vinasse passes through a sequential coagulation and flocculation process in which are eliminated substances of colloidal nature that cause the wastewater's turbidity. These substances are in great part responsible by its high COD, and the clarification is extremely difficult by using conventional centrifugation or filtration processes (see P. Cheremisinoff, "Handbook of Water and Wastewater Treatment Technologies", Butterworth Heinemann, Boston, 2002). The vinasse's coagulation and subsequent flocculation is obtained by raising its pH to levels between 5 and 11 , rather between 7 and 11. This operation is accomplished by agitation using substances as hydroxides, oxides or carbonates from alkaline or alkaline-earth metals or other types of flocculant substances as, for example, ferrous sulphate. The agitation speed is kept between 10 and 30 minutes, rather between 15 and 20 minutes between 300 and 600 rpm, although rather between 400 and 450 rpm. Flocculants percentuals between 0.5% and 5%, rather between 0.8% and 1% are enough to reduce the COD levels from 30% to 55%. Temperatures on the range of 60 ⁰ C to 90 ⁰ C tend to accelerate the coagulation and flocculation process, and beside this range solubilize the flocks formed difficulting the process. The mud resulting from this ffocculation is rich in nitrogen from 1.5 to 2%,

phosphorus from 1.3 to 1.5% and mainly potassium from 1.25 to 1.5%; it might be utilized as fertilizer.

On a typical situation, a vinasse sample containing 3.7% of treated evaporation waste with 1% of calcium oxide supplied some 1.8% of flocculated fertilizer mud with the characteristics of 1.5% of nitrogen (N); 1.27% of phosphate (P) and 1.25% of potassium sulphate (K). The biogas proceeding from biodigester is forced to sparkle on the supernatant fluid. Such operation besides adjusting the effluent's pH to less alkaline levels and on better disposal conditions, transforms occasional remaining hydroxides into carbonates raises the methane yield on biogas, as a consequence | increasing its fuel power.

4 - The following stage has as its purpose to degrade the rest of the remaining organic charge and it is carried out by subjecting the fluid into a process of advanced photo-oxidization (see review by

Vishwas G. Pangarkar et al., J. Chem. Technol. Biotechnol., 77, pp

102-116 (2001)).

On this stage there may be used processes Photo Fenton type, photo-oxidization by using ozone, hydrogen peroxide or other types of substances generators of free radical with a high oxidant power, or even these same systems catalyzed by semiconductors like titanium oxide or zinc oxide.

Necessary energy may be solar or artificially produced light at the visible region or ultraviolet spectral regions. Such stage is determinative to clarify definitely the wastewater which, even though it might not contain traces of opacity, it still presents a stressed color until this moment.

On a typical situation, it was accomplished a direct solar

exposure to supernatant fluid samples obtained on previous stage in titanium dioxide - Anatase coated bottom recipients being treated with ozone by 30 minutes samples of 1 liter with a flow of 0.01 g O ₃ / Liter / Hour added to sample of 1% of Hydrogen Peroxide.

With the exposure of 30 minutes to the sun (mean solar radiation of 90.000 Lux) and using 0.5 cm deep of fluid there were obtained the following colorimetry results with the diluted samples 1 :1 on deionized water:

Results above show an efficient degradation of substances which confer color to vinasse.

5 - The last stage consists on the removal of substances which might remain in solution, mainly of inorganic ions. This is why the solution is forced to pass through adsorbents able to effect ionic changes like ionic change resins, microporous and mesoporous mineral substances as natural or artificial zeolits, natural clays, benthonites or kaolin derivates or even molecular sieves or fissile soils like diatomaceae. While passing through this stage the vinasse has already decreased from 95% to 100% of its organic charge, it has diminished its COD from 80% to 100%, rather from 90% to 100%, with pH between 6.5 and 8.5, rather between 7 and 7.5. Adsorbed ions, specially potassium abundantly present, constitute itself on an excellent fertilizer and water with low COD remaining

from the process may be recycled on irrigations or other purposes.

On a typical situation, regarding the process as a whole, an ozone-treated vinasse sample is forced to pass through a fixed bed biofilter, filled with Luffa cilindrica fragments populated with anaerobic mesophylls resulting from swine feces, being of 12 minutes the solar exposure time. Using 1% of calcium oxide to flocculate the system and a 12 minutes solar exposure after ozonization of 0.01 g O ₃ / liter/ hour with addition of 1% of hydrogen peroxide shows a 35% decrease on the COD level and 23% on the BDO ₅ amount, occurring a increase of 21% on the system biodegradability index ( BDO ₅ / COD ). The wastewater's pH in this stage ϊs between 7.5 and 8.0.

The triplication of times of the mentioned stages induces the system to drops of the order of 80% on the COD and BDO ₅ levels. Raises of 100% on calcium oxide and hydrogen peroxide concentrations induce to similar results, showing that for the treatment of vinasse or of other effluents great flows it is necessary, considering these levels, to correctly dimension de ozonization, biofiltration, flocculation, and photodegradation equipments in order to reach efficient results on the treatment. (The analytical methods used were: COD: Colorimetric Method - proceeding 5220. D - APHA, AWWA, WEF, Standard Methods for the Examination of Water and Wastewater, 20 ed., 1998. BOD ₅ : Electrochemical method (oxymeter use) - proceeding 5210.D - APHA, AWWA, WEF, Standard Methods for the Examination of Water and Wastewater, 20 ed., 1998).

The subject of this descriptive report was, therefore, a new conception on wastewaters disinfection and treatment techniques,

presenting as we could evidence by the analysis accomplished and by the stages shown, a number of differences about the existing conventional process on consumer market, besides of technical and functional characteristics diverse from those pertaining to the state- of-the-art. For the advantages it offers, and also, for being provided with truly innovative characteristics which fulfill all the requisites of the latest state of innovation and originality on its kind, this PROCESS FOR LARGE AMOUNTS OF WASTEWATER DESINFECTION AND TREATMENT, WATER RECYCLING AND UTILIZATION OF ORGANIC AND INORGANIC CHARGES meets the necessary conditions to deserve the Invention Right.